Unauthorized deduction on my salary advice

Lion of Africa Insurance have deducted money from my salary advice without my concent. I called this company to try and find out how this was even possible because this was the first time hearing about such a company, let alone have any policies with them. The lady I spoke to told me that I need to write a letter of complaint stating that I want a refund and said the whole process may take a minimum of 14 days. I am very unhappy with this because I now find myself with a problem that I didn't create.